Transcription by RNA pol II is controlled at both the level of initiation of RNA chains and their elongation into full length primary transcripts. In recent years, it has become clear that in metazoans the regulation of the elongation step is probably as important as the initiation step. Budding yeast is the organism of choice for genetic analysis of transcription, however, regulated elongation in this system is not well established. The first aim of this project is to explore the in vivo mechanisms of RNA pol II recruitment to transcribed genes and elongation of RNA chains by direct analysis of polymerase distribution on and along genes in budding yeast and metazoans. The in vivo cross linking method I have proposed to utilize obviates problems associated with analysis of transcription by measuring steady state mRNA abundance. The second aim, will test whether transcription and mRNA processing are coordinated with one another in budding yeast. pre- mRNA capping, splicing, and cleavage/polyadenylation occur cotranscriptionally in metazoans. The exact mechanism of this coordination is not known, nor is it known whether co-transcriptional mRNA processing occurs in budding yeast. The in vivo cross linking technique applied for the first aim will allow me to examine , protein:protein interactions in vivo between RNA pol II and mRNA processing factors as well as their distribution along genes.